I lost my 2017 IP pin, can I file my 2017 return using 2018 IP pin?

[mesquitebean · Accepted solution]

Yes, you would use a 2018 IP PIN if filing the 2017 return now--not the 2017 IP PIN.

An IP PIN goes by the year that you actually file the return--not the tax year of the return.

So if you file a 2017 return now in 2018, you use the 2018 IP PIN.   When you print the 2017 return,  you'll likely have to manually write in the IP PIN in the proper space in the signature section.

Here's that question from the IP PIN FAQ page at irs.gov:

Q11: Do I have to use the IP PIN I received this year if filing prior year returns this year?

A11: Yes. You must use this IP PIN to confirm your identity on your current tax return and any prior year returns filed during the calendar year.

[mesquitebean]

@kirzon3
As for your 2018 return, here's a tip that may help you if you haven't already filed it.    If you have already filed your 2018 return, then this won't help.

If you plan to efile a 2018 return, then in order to verify the 2018 return at the end, it will ask you to enter your 2017 AGI.   Since you didn't file the 2017 return last year, your 2017 AGI will not be in the IRS database.  So you would enter an AGI of 0 in order to efile the 2018 return.    

Of course, you would need to also enter your 2018 IP PIN in the interview as well.   There's a special topic for the IP PIN entry, just as there was for the IP PIN in your 2017 return.